The South East Bay Plain (SEBP) basin study was conducted to support development of EBMUD’s Groundwater Management Plan (GMP) as part of EBMUD’s efforts to implement conjunctive use to improve water supply reliability. The project study area includes the City of Hayward.

The project included the following activities:

Converting an existing Integrated Groundwater and Surface Water Model (IGSM) to a USGS MODFLOW model; updating the model to reflect the improved groundwater basin understanding; calibrating the model for the SEBP study area; and making recommendations for additional improvements to the model

Compiling and reviewing previous studies and groundwater investigations completed in or adjacent to the SEBP study area

Developing a hydrogeologic conceptual model by updating hydrogeologic cross-sections developed in previous technical studies with new basin information

Documenting the SEBP basin characteristics; delineating basin boundaries; and establishing the baseline hydrogeologic conditions of the SEBP basin in a technical report

Documenting the methodology for the groundwater model update

This project also included development of a cost-effective approach utilizing state-of-the-art Arc Hydro tools (including Arc Hydro Groundwater Toolkit and ArcGIS) to quickly update EBMUD’s cross-sections and develop maps and groundwater models in an ESRI environment. The ArcHydro Groundwater Tools were used to evaluate existing conditions and pre-process information for the model update.